The effects of single doses of intramuscularly administered opiates (heroin, morphine, hydromorphone, codeine, oxycodone, oxymorphone) and sublingual buprenorphine are being studied in male human volunteers in order to determine the relationship of blood and saliva levels to pharmacologic effects. Additionally, the study is being performed to determine if a metabolic marker for heroin abuse can be found in urine. The subjects are healthy males with a history of heroin abuse. Informed consent is is obtained and all procedures are approved by the hospital Institutional Review Board. A total of three test doses (placebo and two active doses) are administered in random order. Test measures are made for 24 hrs and biological fluids are collected for 7 days after each test. The biological fluids will be analyzed for drug and metabolites by chromatographic and immunoassay techniques. The significance of this study lies in the potential value of saliva as a new test medium for detection of drugs of abuse and the characterization of the time course of excretion of metabolic markers for heroin and other opiates in urine and saliva.